Need help choosing emitter for aspheric Mag

I have decided to look into upgrading the LED in my 2D aspheric Mag.

I looked around on DX for a driver. I have come up with these two.

1. http://www.dealextreme.com/p/2-7v-6v-3w-cree-circuit-board-for-flashlights-15mm-2-7mm-25518

2.http://www.dealextreme.com/p/2-7-4-...ry-circuit-board-for-flashlights-16-8mm-50525

I do not know which Cree (or SSC) LED emitter to use. I'd like to know which one will work best in an aspheric Mag. I planned on having it run on 2D's but I can upgrade to with 2 3AA to D adapters if needed, and I would like it to have at least 300 Lumens of output.

All your help is wanted!

Everyone says the XR-E R2 works the best with an aspheric lens. If you are looking into DX drivers, have a look at SKU.6190.

Thanks Al Combs.

I found these two products.

http://www.dealextreme.com/p/cree-xr-e-r2-wg-emitter-on-premium-star-15943
http://www.dealextreme.com/p/5-mode-1000ma-7135-circuit-board-for-cree-and-ssc-emitters-6190

Now I just need a heatsink. I found these, http://www.candlepowerforums.com/vb/showthread.php?310770-********-H22A-Heatsinks I could possibly use the lathe and turn the post down the the led sits nice and snug down in the heatsink.

If I run this at 3V, from 2D cells, is there a way I could figure about how many lumens the LED will emit?

Thanks Al Combs.

I found these two products.

http://www.dealextreme.com/p/cree-xr-e-r2-wg-emitter-on-premium-star-15943
http://www.dealextreme.com/p/5-mode-1000ma-7135-circuit-board-for-cree-and-ssc-emitters-6190

Now I just need a heatsink. I found these, http://www.candlepowerforums.com/vb/showthread.php?310770-********-H22A-Heatsinks I could possibly use the lathe and turn the post down so the the led sits nice and snug down in the heatsink.

If I run this at 3V, from 2D cells, is there a way I could figure about how many lumens the LED will emit?

Not many lumens at all... you will need another circuit that will step up the voltage to something like 3,6Volts. The circuit you linked to is a current regulator, wich will do nothing at 3V with a Cree R2.

The two DX links are the right ones. Also +1 to H22A's heatsinks being a good pick. The picture of the R2 from DX shows the newer EZ900 die. You can tell by the copper fringe around the phosphor. The LED measures 0.9 mm on a side instead of the original 1 mm die. The same lumens coming from a smaller area makes the lux reading for aspherics higher. Not as important for reflector based lights. But it's the best available for an aspheric. And now for the bad news... Do you see the green check mark in the middle of the page? Whenever DX says, "Typically ships in 4 to 7 days", it means they don't have it but it's still available. When an item is in stock it will say, "In Stock: ships in 2 to 4 days". I hope you're not in a rush. For 41¢ more, SKU.7612 is both in stock and has a mode with no SOS or strobe. It also has a blank spot on the board if you happen to have an extra 7135 chip lying around for 1.4 amps. That's pushing it a bit. But many people have driven the XR-E that hard with no problem.

Scattergun is right about the 2D cells. If you want to use regular alkaline batteries, you need a 3D for full power. As to output, you can find the Cree data sheets here. The binning & labeling pdf normally has the output range for a particular bin rating. But for some reason the R2 bin was never included in the XR-E B&L.:shrug: The bins for the XP-G are the same. Anyway, the XR-E R2 bin ranges in output @350 ma from 114-122 lumens. An inference from the Relative Flux vs. Current graph on page 8 of the data sheet give a 1 amp range of 251.8-269.5 lumens. That's based on a ratio of 2.209. It's probably not that exact but will give you a good idea.

Would that work to get 2 2AAtoD adapters wired in series? I don't have a 3D mag on hand.

I don't know how easy if would be to change AA-D cell adapters to series. Or how well AA alkalines would stand up to high drain. I guessed you meant Alkaline batteries when you said 3v from 2D. If they do hold their voltage well, it might be too much heat for the linear regulator.

Instead of the AA-D adapters, you could also put 3 C cells in a 2D with a modified tailcap spring. It would work much better than 4*AA's. A 5" long piece of of 1" diameter Schedule 40 PVC from the local hardware store will make a good spacer. There is about ≈¼" of space between the end of the last battery and the inside of the tailcap when screwed in place. More than enough for a homemade spring of some sort. A Google of CPF for "MagLite tailcap spring" will give you some ideas.

Here's jtr1962 test on the XR-E R2. This will give you a idea of what output you'll have with what ever driver current you choose.